Patent document 1 described below discloses an example of a vehicle door operation device of this kind (a vehicle door operation device). The vehicle door operation device is mounted to a sliding door, and is configured to be able to release a door latch of a latch mechanism for the sliding door (a closure retention of the sliding door) by using a power of a release motor. In particular, the vehicle door operation device includes an open lever (a ratchet interlock lever), an outside handle lever (a vehicle exterior handle interlock lever), a motor power transmission lever, and a cancellation mechanism. The open lever operates the latch mechanism. The outside handle lever interlocks with the open lever. The motor power transmission lever operates by the release motor. The cancellation mechanism deals with, for example, an electrical failure of the release motor. In a case where the latch mechanism maintains to release the closure retention of the sliding door because the motor power transmission lever is retained at a rotary end position due to, for example, the electrical failure of the release motor when the motor power transmission lever is disposed at the rotary end position, the cancellation mechanism cancels this state. For this purpose, the cancellation mechanism is configured to move a connection member, connecting the motor power transmission lever and the outside handle lever so as to be able to transmit the power to each other, from a power transmission position to a power disconnection position via an inside handle lever (a vehicle interior handle interlock lever) operating by a closing operation of an inside handle. According to the cancellation mechanism, the outside handle lever can integrally rotate with the open lever by being disconnected from the motor power transmission lever and perform the closure retention of the sliding door by the latch mechanism by returning the open lever to an initial position.